[Octave-bug-tracker] [bug #53299] Several rand/randn bugs with state/seed behavior.

[Mike Miller]

Follow-up Comment #6, bug #53299 (project octave):

I'm not sure this is worth pursuing, but I have noticed this odd behavior when
testing the rand functions:


## just started Octave (with --norc), rand generator is in some indeterminate
state
>> init_state = rand ('state');
>> init_seed = rand ('seed');
>> x = rand (100); ## generate a few numbers to shift the state
>> isequal (init_seed, rand ('seed'))  ## NOT using 'seed'
ans = 1
>> isequal (init_state, rand ('state'))
## now let's try to go back to the initial state
>> rand ('state', init_state);
>> y = rand (100);
>> isequal (x, y)
ans = 0
## uh oh, they should be equal, let's try again
>> rand ('state', init_state);
>> z = rand (100);
>> isequal (x, z)
ans = 0
>> isequal (y, z)
ans = 1


As far as I can tell, setting the rand state does reset the rand generator to
a known state and the same sequence is produced. However, when Octave first
starts, the vector that is returned from rand('state') is not the actual
initial state.

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